Juicers for foodstuffs, such as fruit or vegetables, are known for separating juice from pulp. Such apparatus are highly popular because of their health and taste benefits. One form of juicer is a centrifugal juicer.
A centrifugal juicer is shown in FIG. 1. Such a juicer 1 comprises a housing 2 with a rotating body 3 which is rotatably mounted in the housing 2. The rotating body 3 comprises a base 4, a grater 5 mounted on an upper surface of the base 4 and a sieve 6 upstanding around the periphery of the base 4 and diverging outwardly in a conical shape to form a fruit or vegetable receiving chamber 7. A cylindrical guide 8 feeds fruit into the chamber 7, a juice outlet 9 is formed around the outer face of the sieve 6 to receive juice urged through the sieve 6, and a pulp outlet 11 is formed at the upper end of the sieve 6 to receive pulp urged from the chamber 7.
When the rotating body 3 is rotated by a motor 12, the sieve 6 and grater 5 are rotated. A fruit or vegetable inserted into the juicer is guided by the guide 8 onto the grater 5 and reduced to pulp and juice. The pulp and juice is then urged radially outwards by the centrifugal force of the rotating body 3. The sieve 6 has a plurality of perforations or holes 13 in it through which juice is urged to flow, but the pulp is retained in the body 3 so that the juice separated from the pulp and flows into the juice outlet 9. The pulp retained in the chamber 7 and is urged upwardly towards the pulp outlet 11.
However, a recognised problem of a centrifugal juicer is that it is difficult and time consuming for a user to clean. In particular, the fibres of the pulp get stuck in the perforations of the sieve and so a user has to brush the sieve by hand to clean it.
Furthermore, it is known that the size of the perforations or holes formed through the sieve are generally greater in diameter than the size of the pulp particles from which juice is to be separated. With a conventional sieve, the inner surface of the sieve is quickly covered with fibres so that the initial fibres cover the holes in the sieve, and themselves become the sieve. This is known in the industry as cake filtration process. However, it will be appreciated that the sieve only works when dirty and such an arrangement is inefficient as the fibres coat the whole of the sieve, and so the effectiveness of the sieve is reduced as the sieve does not work until its inner surface has been thoroughly covered in pulp.